Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise Neff evaluation
Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise Neff evaluation
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超越标准模型的中微子解耦：通过快速、精确的 Neff 评估对暗物质质量的 CMB 约束
DOI：
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发表时间：
2018
影响因子：
6.4
通讯作者：
M. Escudero
中科院分区：
文献类型：
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作者：
M. Escudero
有效相对论中微子种类的数量代表了早期宇宙热历史的基本探测，也是粒子物理学标准模型的基本探测。传统的中微子退耦方法要么是非常技术和计算昂贵的，或者假设中微子瞬间退耦。在这项工作中，我们的目标是填补这两种方法之间的差距建模中微子去耦的两个简单的耦合微分方程的电磁和中微子部门的温度，其中所有相关的相互作用都考虑在内，并允许一个简单的实施BSM物种。在包括有限温度QED修正后，我们达到了0.01的SM的Neff的精度。我们说明了这种方法的有用性的中微子去耦考虑，在一个模型独立的方式，MeV的热暗物质对Neff的影响。我们表明，普朗克排除了亲电和亲中微子的热暗物质粒子的m< 3.8 MeV在95% CL，无论他们的自旋，和他们的湮灭是s波或p波。我们指出，热暗物质粒子与电子和中微子的不可忽略的相互作用是更难以捉摸的CMB观测比纯粹的亲电或亲中微子的。此外，我们的方法的准确性的帮助下，我们表明，CMB第四阶段的实验将一般测试热暗物质粒子与m 20兆电子伏。我们在https://github.com/MiguelEA/nudec_BSM上公开了为本研究开发的代码。
The number of effective relativistic neutrino species represents a fundamental probe of the thermal history of the early Universe, and as such of the Standard Model of Particle Physics. Traditional approaches to the neutrino decoupling are either very technical and computationally expensive, or assume that neutrinos decouple instantaneously. In this work, we aim to fill the gap between these two approaches by modeling the neutrino decoupling in terms of two simple coupled differential equations for the electromagnetic and neutrino sector temperatures, in which all the relevant interactions are taken into account and which allows for a straightforward implementation of BSM species. Upon including finite temperature QED corrections we reach an accuracy on Neff in the SM of 0.01. We illustrate the usefulness of this approach to the neutrino decoupling by considering, in a model independent manner, the impact of MeV thermal dark matter on Neff. We show that Planck rules out electrophilic and neutrinophilic thermal dark matter particles of m< 3.8 MeV at 95% CL regardless of their spin, and of their annihilation being s-wave or p-wave. We point out that thermal dark matter particles with non-negligible interactions with both electrons and neutrinos are more elusive to CMB observations than purely electrophilic or neutrinophilic ones. In addition, assisted by the accuracy of our approach, we show that CMB Stage-IV experiments will generically test thermal dark matter particles with m ≲ 20 MeV. We make publicly available the codes developed for this study at this https://github.com/MiguelEA/nudec_BSM.
影响因子：
5
作者：
K. Nakamura;K. Hagiwara;K. Hikasa;H. Murayama;M. Tanabashi;T. Watari;C. Amsler;M. Antonelli
通讯作者：
K. Nakamura;K. Hagiwara;K. Hikasa;H. Murayama;M. Tanabashi;T. Watari;C. Amsler;M. Antonelli